diff --git a/src/components/LeftSidebar/ConversationsList/Conversation.spec.js b/src/components/LeftSidebar/ConversationsList/Conversation.spec.js
index a6434108e8e..5a6ab3ad4fd 100644
--- a/src/components/LeftSidebar/ConversationsList/Conversation.spec.js
+++ b/src/components/LeftSidebar/ConversationsList/Conversation.spec.js
@@ -530,10 +530,22 @@ describe('Conversation.vue', () => {
 
 			expect(toggleFavoriteAction).toHaveBeenCalledWith(expect.anything(), item)
 		})
+		test('marks conversation as unread', async () => {
+			const markConversationUnreadAction = jest.fn().mockResolvedValueOnce()
+			testStoreConfig.modules.conversationsStore.actions.markConversationUnread = markConversationUnreadAction
+
+			const action = shallowMountAndGetAction('Mark as unread')
+			expect(action.exists()).toBe(true)
+
+			await action.find('button').trigger('click')
+
+			expect(markConversationUnreadAction).toHaveBeenCalledWith(expect.anything(), { token: item.token })
+		})
 		test('marks conversation as read', async () => {
 			const clearLastReadMessageAction = jest.fn().mockResolvedValueOnce()
 			testStoreConfig.modules.conversationsStore.actions.clearLastReadMessage = clearLastReadMessageAction
 
+			item.unreadMessages = 1
 			const action = shallowMountAndGetAction('Mark as read')
 			expect(action.exists()).toBe(true)
 
diff --git a/src/components/LeftSidebar/ConversationsList/Conversation.vue b/src/components/LeftSidebar/ConversationsList/Conversation.vue
index 94224fd844e..1376e4997b3 100644
--- a/src/components/LeftSidebar/ConversationsList/Conversation.vue
+++ b/src/components/LeftSidebar/ConversationsList/Conversation.vue
@@ -62,13 +62,22 @@
 				@click.stop.prevent="handleCopyLink">
 				{{ t('spreed', 'Copy link') }}
 			</NcActionButton>
-			<NcActionButton :close-after-click="true"
+			<NcActionButton v-if="item.unreadMessages"
+				:close-after-click="true"
 				@click.prevent.exact="markConversationAsRead">
 				<template #icon>
 					<EyeOutline :size="16" />
 				</template>
 				{{ t('spreed', 'Mark as read') }}
 			</NcActionButton>
+			<NcActionButton v-else
+				:close-after-click="true"
+				@click.prevent.exact="markConversationAsUnread">
+				<template #icon>
+					<EyeOffOutline :size="16" />
+				</template>
+				{{ t('spreed', 'Mark as unread') }}
+			</NcActionButton>
 			<NcActionButton :close-after-click="true"
 				@click.prevent.exact="showConversationSettings">
 				<Cog slot="icon"
@@ -116,6 +125,7 @@ import ArrowRight from 'vue-material-design-icons/ArrowRight.vue'
 import Cog from 'vue-material-design-icons/Cog.vue'
 import Delete from 'vue-material-design-icons/Delete.vue'
 import ExitToApp from 'vue-material-design-icons/ExitToApp.vue'
+import EyeOffOutline from 'vue-material-design-icons/EyeOffOutline.vue'
 import EyeOutline from 'vue-material-design-icons/EyeOutline.vue'
 import Star from 'vue-material-design-icons/Star.vue'
 
@@ -134,14 +144,16 @@ export default {
 	name: 'Conversation',
 
 	components: {
+		ConversationIcon,
+		NcActionButton,
+		NcListItem,
+		// Icons
 		ArrowRight,
 		Cog,
-		ConversationIcon,
 		Delete,
 		ExitToApp,
+		EyeOffOutline,
 		EyeOutline,
-		NcActionButton,
-		NcListItem,
 		Star,
 	},
 
@@ -350,6 +362,10 @@ export default {
 			this.$store.dispatch('clearLastReadMessage', { token: this.item.token })
 		},
 
+		markConversationAsUnread() {
+			this.$store.dispatch('markConversationUnread', { token: this.item.token })
+		},
+
 		showConversationSettings() {
 			emit('show-conversation-settings', { token: this.item.token })
 		},
diff --git a/src/services/conversationsService.js b/src/services/conversationsService.js
index 4db22f54663..bafe44813ee 100644
--- a/src/services/conversationsService.js
+++ b/src/services/conversationsService.js
@@ -206,6 +206,20 @@ const clearConversationHistory = async function(token) {
 	return response
 }
 
+/**
+ * Set conversation as unread
+ *
+ * @param {string} token The token of the conversation to be set as unread
+ */
+const setConversationUnread = async function(token) {
+	try {
+		const response = axios.delete(generateOcsUrl('apps/spreed/api/v1/chat/{token}/read', { token }))
+		return response
+	} catch (error) {
+		console.debug('Error while setting the conversation as unread: ', error)
+	}
+}
+
 /**
  * Add a conversation to the favorites
  *
@@ -433,6 +447,7 @@ export {
 	setConversationName,
 	setConversationDescription,
 	clearConversationHistory,
+	setConversationUnread,
 	setConversationPermissions,
 	setCallPermissions,
 	setMessageExpiration,
diff --git a/src/store/conversationsStore.js b/src/store/conversationsStore.js
index 85a7b488b49..10048cf3d44 100644
--- a/src/store/conversationsStore.js
+++ b/src/store/conversationsStore.js
@@ -46,6 +46,7 @@ import {
 	setConversationDescription,
 	deleteConversation,
 	clearConversationHistory,
+	setConversationUnread,
 	setNotificationLevel,
 	setNotificationCalls,
 	setConversationPermissions,
@@ -121,13 +122,13 @@ const mutations = {
 	 * Deletes a conversation from the store.
 	 *
 	 * @param {object} state current store state;
-	 * @param {object} token the token of the conversation to delete;
+	 * @param {string} token the token of the conversation to delete;
 	 */
 	deleteConversation(state, token) {
 		Vue.delete(state.conversations, token)
 	},
 	/**
-	 * Resets the store to it's original state
+	 * Resets the store to its original state
 	 *
 	 * @param {object} state current store state;
 	 */
@@ -198,7 +199,7 @@ const mutations = {
 
 const actions = {
 	/**
-	 * Add a conversation to the store and index the displayname.
+	 * Add a conversation to the store and index the displayName.
 	 *
 	 * @param {object} context default store context;
 	 * @param {object} conversation the conversation;
@@ -211,8 +212,8 @@ const actions = {
 			displayName: context.getters.getDisplayName(),
 		}
 
-		// Fallback to getCurrentUser() only if if has not been set yet (as
-		// getCurrentUser() needs to be overriden in public share pages as it
+		// Fallback to getCurrentUser() only if it has not been set yet (as
+		// getCurrentUser() needs to be overridden in public share pages as it
 		// always returns an anonymous user).
 		if (!currentUser.uid) {
 			currentUser = getCurrentUser()
@@ -250,7 +251,7 @@ const actions = {
 	 *
 	 * @param {object} context default store context;
 	 * @param {object} data the wrapping object;
-	 * @param {object} data.token the token of the conversation to be deleted;
+	 * @param {string} data.token the token of the conversation to be deleted;
 	 */
 	async deleteConversationFromServer(context, { token }) {
 		await deleteConversation(token)
@@ -263,7 +264,7 @@ const actions = {
 	 *
 	 * @param {object} context default store context;
 	 * @param {object} data the wrapping object;
-	 * @param {object} data.token the token of the conversation whose history is
+	 * @param {string} data.token the token of the conversation whose history is
 	 * to be cleared;
 	 */
 	async clearConversationHistory(context, { token }) {
@@ -279,7 +280,7 @@ const actions = {
 	},
 
 	/**
-	 * Resets the store to it's original state.
+	 * Resets the store to its original state.
 	 *
 	 * @param {object} context default store context;
 	 */
@@ -289,11 +290,11 @@ const actions = {
 	},
 
 	async toggleGuests({ commit, getters }, { token, allowGuests }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
+		const conversation = Object.assign({}, getters.conversations[token])
 		if (allowGuests) {
 			await makePublic(token)
 			conversation.type = CONVERSATION.TYPE.PUBLIC
@@ -306,8 +307,7 @@ const actions = {
 	},
 
 	async toggleFavorite({ commit, getters }, { token, isFavorite }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
@@ -317,17 +317,18 @@ const actions = {
 		} else {
 			await addToFavorites(token)
 		}
-		conversation.isFavorite = !isFavorite
+
+		const conversation = Object.assign({}, getters.conversations[token], { isFavorite: !isFavorite })
 
 		commit('addConversation', conversation)
 	},
 
 	async toggleLobby({ commit, getters }, { token, enableLobby }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
+		const conversation = Object.assign({}, getters.conversations[token])
 		if (enableLobby) {
 			await changeLobbyState(token, WEBINAR.LOBBY.NON_MODERATORS)
 			conversation.lobbyState = WEBINAR.LOBBY.NON_MODERATORS
@@ -340,13 +341,13 @@ const actions = {
 	},
 
 	async setConversationName({ commit, getters }, { token, name }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
 		await setConversationName(token, name)
-		conversation.displayName = name
+
+		const conversation = Object.assign({}, getters.conversations[token], { displayName: name })
 
 		commit('addConversation', conversation)
 	},
@@ -366,102 +367,107 @@ const actions = {
 	},
 
 	async setReadOnlyState({ commit, getters }, { token, readOnly }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
 		await changeReadOnlyState(token, readOnly)
-		conversation.readOnly = readOnly
+
+		const conversation = Object.assign({}, getters.conversations[token], { readOnly })
 
 		commit('addConversation', conversation)
 	},
 
 	async setListable({ commit, getters }, { token, listable }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
 		await changeListable(token, listable)
-		conversation.listable = listable
+
+		const conversation = Object.assign({}, getters.conversations[token], { listable })
 
 		commit('addConversation', conversation)
 	},
 
 	async setLobbyTimer({ commit, getters }, { token, timestamp }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
+		const conversation = Object.assign({}, getters.conversations[token], { lobbyTimer: timestamp })
+
 		// The backend requires the state and timestamp to be set together.
 		await changeLobbyState(token, conversation.lobbyState, timestamp)
-		conversation.lobbyTimer = timestamp
 
 		commit('addConversation', conversation)
 	},
 
 	async setSIPEnabled({ commit, getters }, { token, state }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
 		await setSIPEnabled(token, state)
-		conversation.sipEnabled = state
+
+		const conversation = Object.assign({}, getters.conversations[token], { sipEnabled: state })
 
 		commit('addConversation', conversation)
 	},
 
 	async setConversationProperties({ commit, getters }, { token, properties }) {
-		let conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
-		conversation = Object.assign(conversation, properties)
+		const conversation = Object.assign({}, getters.conversations[token], properties)
 
 		commit('addConversation', conversation)
 	},
 
 	async markConversationRead({ commit, getters }, token) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
-		conversation.unreadMessages = 0
-		conversation.unreadMention = false
+		commit('updateUnreadMessages', { token, unreadMessages: 0, unreadMention: false })
+	},
 
-		commit('addConversation', conversation)
+	async markConversationUnread({ commit, dispatch, getters }, { token }) {
+		if (!getters.conversations[token]) {
+			return
+		}
+
+		await setConversationUnread(token)
+		commit('updateUnreadMessages', { token, unreadMessages: 1 })
+		await dispatch('fetchConversation', { token })
 	},
 
 	async updateLastCommonReadMessage({ commit, getters }, { token, lastCommonReadMessage }) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
-		conversation.lastCommonReadMessage = lastCommonReadMessage
+		const conversation = Object.assign({}, getters.conversations[token], { lastCommonReadMessage })
 
 		commit('addConversation', conversation)
 	},
 
 	async updateConversationLastActive({ commit, getters }, token) {
-		const conversation = Object.assign({}, getters.conversations[token])
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			return
 		}
 
-		conversation.lastActivity = (new Date().getTime()) / 1000
+		const conversation = Object.assign({}, getters.conversations[token], {
+			lastActivity: (new Date().getTime()) / 1000,
+		})
 
 		commit('addConversation', conversation)
 	},
 
 	async updateConversationLastMessage({ commit }, { token, lastMessage }) {
 		/**
-		 * Only use the last message as lastmessage when:
+		 * Only use the last message as lastMessage when:
 		 * 1. It's not a command reply
 		 * 2. It's not a temporary message starting with "/" which is a user posting a command
 		 * 3. It's not a reaction or deletion of a reaction
@@ -483,13 +489,14 @@ const actions = {
 
 	async updateConversationLastMessageFromNotification({ getters, commit }, { notification }) {
 		const [token, messageId] = notification.objectId.split('/')
-		const conversation = { ...getters.conversation(token) }
 
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			// Conversation not loaded yet, skipping
 			return
 		}
 
+		const conversation = Object.assign({}, getters.conversations[token])
+
 		const actor = notification.subjectRichParameters.user || notification.subjectRichParameters.guest || {
 			type: 'guest',
 			id: 'unknown',
@@ -547,29 +554,32 @@ const actions = {
 
 	async updateCallStateFromNotification({ getters, commit }, { notification }) {
 		const token = notification.objectId
-		const conversation = { ...getters.conversation(token) }
 
-		if (!conversation) {
+		if (!getters.conversations[token]) {
 			// Conversation not loaded yet, skipping
 			return
 		}
 
-		conversation.hasCall = true
-		conversation.callFlag = PARTICIPANT.CALL_FLAG.WITH_VIDEO
-		conversation.activeSince = (new Date(notification.datetime)).getTime() / 1000
-		conversation.lastActivity = conversation.activeSince
-		conversation.callStartTime = conversation.activeSince
+		const activeSince = (new Date(notification.datetime)).getTime() / 1000
+
+		const conversation = Object.assign({}, getters.conversations[token], {
+			hasCall: true,
+			callFlag: PARTICIPANT.CALL_FLAG.WITH_VIDEO,
+			activeSince,
+			lastActivity: activeSince,
+			callStartTime: activeSince,
+		})
 
 		// Inaccurate but best effort from here on:
 		const lastMessage = {
 			token,
-			id: 'temp' + conversation.activeSince,
+			id: 'temp' + activeSince,
 			actorType: 'guests',
 			actorId: 'unknown',
 			actorDisplayName: t('spreed', 'Guest'),
 			message: notification.subjectRich,
 			messageParameters: notification.subjectRichParameters,
-			timestamp: conversation.activeSince,
+			timestamp: activeSince,
 			messageType: 'system',
 			systemMessage: 'call_started',
 			expirationTimestamp: 0,
diff --git a/src/store/conversationsStore.spec.js b/src/store/conversationsStore.spec.js
index 741fd6c6f5b..54a7ecde2b6 100644
--- a/src/store/conversationsStore.spec.js
+++ b/src/store/conversationsStore.spec.js
@@ -1,4 +1,5 @@
 import { createLocalVue } from '@vue/test-utils'
+import flushPromises from 'flush-promises'
 import { cloneDeep } from 'lodash'
 import Vuex from 'vuex'
 
@@ -26,6 +27,7 @@ import {
 	deleteConversation,
 	setConversationPermissions,
 	setCallPermissions,
+	setConversationUnread,
 } from '../services/conversationsService.js'
 import storeConfig from './storeConfig.js'
 
@@ -47,6 +49,7 @@ jest.mock('../services/conversationsService', () => ({
 	deleteConversation: jest.fn(),
 	setConversationPermissions: jest.fn(),
 	setCallPermissions: jest.fn(),
+	setConversationUnread: jest.fn(),
 }))
 
 describe('conversationsStore', () => {
@@ -583,6 +586,31 @@ describe('conversationsStore', () => {
 			expect(changedConversation.unreadMention).toBe(false)
 		})
 
+		test('marks conversation as unread', async () => {
+			testConversation.unreadMessages = 0
+
+			const response = {
+				data: {
+					ocs: {
+						data: { ...testConversation, unreadMessages: 1 },
+					},
+				},
+			}
+			fetchConversation.mockResolvedValue(response)
+
+			store.dispatch('addConversation', testConversation)
+
+			store.dispatch('markConversationUnread', { token: testToken })
+
+			await flushPromises()
+
+			expect(setConversationUnread).toHaveBeenCalled()
+			expect(fetchConversation).toHaveBeenCalled()
+
+			const changedConversation = store.getters.conversation(testToken)
+			expect(changedConversation.unreadMessages).toBe(1)
+		})
+
 		test('updates last common read message', () => {
 			testConversation.lastCommonReadMessage = {
 				id: 999,